A typical semiconductor manufacturing apparatus includes a temperature adjustment system using a PID (Proportional-Integral-Derivative) control to adjust the temperature of a chemical solution in a chemical solution bath for etching or the like, or to adjust the temperature of a chemical solution used in, for instance, a single-wafer cleaner for semiconductors (see, for instance, Patent Literature 1).
In the PID control, PID constants such as a proportional gain Kp, an integral time Ti and a derivative time Td are determined and the temperature control system is controlled with the determined PID constants.
As typically known, the PID constants are determined by: (1) repeating a manual trial and error approach; (2) conducting an experiment; (3) using an auto-tuning function provided to the temperature adjustment system; or (4) adjusting the PID constants using a self-tuning function provided to the temperature adjustment system during operation.